Modeling nonharmonic behavior of materials from experimental inelastic neutron scattering and thermal expansion measurements
Based on thermodynamic principles, we derive expressions quantifying the nonharmonic vibrational behavior of materials, which are rigorous yet easily evaluated from experimentally available data for the thermal expansion coefficient and the phonon density of states. These experimentallyderived quantities are valuable to benchmark firstprinciples theoretical predictions of harmonic and nonharmonic thermal behaviors using perturbation theory, ab initio moleculardynamics, or MonteCarlo simulations. In this study, we illustrate this analysis by computing the harmonic, dilational, and anharmonic contributions to the entropy, internal energy, and free energy of elemental aluminum and the ordered compound FeSi over a wide range of temperature. Our results agree well with previous data in the literature and provide an efficient approach to estimate anharmonic effects in materials.
 Authors:

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^{[2]};
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^{[3]}
 Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
 Univ. at Buffalo, NY (United States)
 Duke Univ., Durham, NC (United States)
 Publication Date:
 Grant/Contract Number:
 AC0500OR22725
 Type:
 Accepted Manuscript
 Journal Name:
 Journal of Physics. Condensed Matter
 Additional Journal Information:
 Journal Volume: 28; Journal Issue: 38; Journal ID: ISSN 09538984
 Publisher:
 IOP Publishing
 Research Org:
 Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
 Sponsoring Org:
 USDOE Office of Science (SC)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; anharmonicity; aluminum; FeSi; free energy; entropy; inelastic neutron scattering; thermal expansion
 OSTI Identifier:
 1311243
Bansal, Dipanshu, Aref, Amjad, Dargush, Gary, and Delaire, Olivier A. Modeling nonharmonic behavior of materials from experimental inelastic neutron scattering and thermal expansion measurements. United States: N. p.,
Web. doi:10.1088/09538984/28/38/385201.
Bansal, Dipanshu, Aref, Amjad, Dargush, Gary, & Delaire, Olivier A. Modeling nonharmonic behavior of materials from experimental inelastic neutron scattering and thermal expansion measurements. United States. doi:10.1088/09538984/28/38/385201.
Bansal, Dipanshu, Aref, Amjad, Dargush, Gary, and Delaire, Olivier A. 2016.
"Modeling nonharmonic behavior of materials from experimental inelastic neutron scattering and thermal expansion measurements". United States.
doi:10.1088/09538984/28/38/385201. https://www.osti.gov/servlets/purl/1311243.
@article{osti_1311243,
title = {Modeling nonharmonic behavior of materials from experimental inelastic neutron scattering and thermal expansion measurements},
author = {Bansal, Dipanshu and Aref, Amjad and Dargush, Gary and Delaire, Olivier A.},
abstractNote = {Based on thermodynamic principles, we derive expressions quantifying the nonharmonic vibrational behavior of materials, which are rigorous yet easily evaluated from experimentally available data for the thermal expansion coefficient and the phonon density of states. These experimentallyderived quantities are valuable to benchmark firstprinciples theoretical predictions of harmonic and nonharmonic thermal behaviors using perturbation theory, ab initio moleculardynamics, or MonteCarlo simulations. In this study, we illustrate this analysis by computing the harmonic, dilational, and anharmonic contributions to the entropy, internal energy, and free energy of elemental aluminum and the ordered compound FeSi over a wide range of temperature. Our results agree well with previous data in the literature and provide an efficient approach to estimate anharmonic effects in materials.},
doi = {10.1088/09538984/28/38/385201},
journal = {Journal of Physics. Condensed Matter},
number = 38,
volume = 28,
place = {United States},
year = {2016},
month = {7}
}